Rotary perforating apparatus

ABSTRACT

A rotary film perforating apparatus for making the edge perforations in photographic film comprising a rotary wheel carrying on its periphery closely spaced individual perforator assemblies. Each perforator assembly comprises a base fitted with a die element and a pivotable perforator arm carrying a punch element and both elements may be readily removed from the assembly. The arm frictionally engages wall portions of the die element to thereby receive exact guidance with respect to the die. The material hardness of the arm is greater than that of the die so that the arm does not wear out and the replacement of a used die element by a new one entails automatically a renewal of the guidance of the perforator arm.

I United States Patent [151 3,66 1,044 Duden et al. 51 May 9, 1972 [54] ROTARY PERFORATING APPARATUS 56] References Cited UNITED TATES P TEN S [72] Inventors: Emanuel Hubert Duden, Mortsel; Joseph S A T M i Cappuyns, Bel-chem, both f Be|gi 2,760,576 8/1956 Spencer ..83/337 X um 2,963,932 l2/l960 Glueck Primary Examiner-Frank T. Yost [73] Assignee. Gevaert AGFA N.V., Morstel, Belgium Anomey wihiam J Daniel {22] Filed: May 8, 1970 57 ABSTRACT [21 1 App]. No.: 35,710 A rotary film perforating apparatus for making the edge perforations in photographic film comprising a rotary wheel carrying on its periphery closely spaced individual perforator as- [30] Apphcauon Pnomy Dam semblies. Each perforator assembly comprises a base fitted Mav 9. 1969 Great Britain ..23,828/69 with a die element and a PM"ranor carrying a punch element and both elements may be readily removed from the assembly. The arm frictionally engages wall portions [52] US. Cl ..83/100, 83/152, 83/322, of the die element to thereby receive exact guidance with 83/337 83/345 respect to the die. The material hardness of the arm is greater [51 Int. Cl. ..B26f 1/08 than that f the die so that the arm does not wear out and the Field of Search replacement of a used die element by a new one entails automatically a renewal ofthe guidance ofthe perforator arm.

15 Claims, 13 Drawing Figures PATENTEDMY 9l972 3,661,044

sum 1 or 6 PATENTEDMAY 9 I972 SHEET H 0F 6 PATENTEDMAY 91912 SHEET 5 [IF 6 Fig. 70

PATENTEBMAY 9 I972 SHEET 6 [IF 6 Fig. 11

ROTARY PERFORATING APPARATUS The present invention relates to a rotary perforating ap paratus for forming the guide perforations in photographic film and the like.

The perforating of photographic film is necessarily a precise operating in that close tolerances must be maintained for the reason that a perfect leading of the film is possible only when there is exact matching and engagement of the teeth of feed sprocket wheels with the perforations in the film. Economy in manufacturing practice requires that film perforation be accomplished at high speeds, say greater than 100 m/min, and therefore perforating apparatus of the rotary type have been developed which comprise a plurality of individual perforator assemblies which are absolutely fixed in their orientation with respect to the driving mechanism and which may be readily removed for sharpening or servicing.

The present invention aims to provide an improved rotary perforating apparatus wherein a high precision of perforation is obtained, and wherein the replacement of a used die element by a new one entails automatically a renewal of the guidance of the perforator arm which supports the cooperating punch element.

The rotary perforating apparatus according to the present invention comprises:

a frame;

at least one cam member which is provided with a camming surface and which is mounted in a stationary way on said frame;

a web-supporting wheel rotatably joumalled in respect of said frame and said at least one cam member;

a plurality of web perforator assemblies secured to the outside periphery of said web-supporting wheel in fixed circumferential relationship to each other, each web perforator assembly comprising a base member, at least one perforator arm movable relative to said base member and supporting an exchangeable punch element, and an associated exchangeable die element secured to the base member, each said perforator arm cooperating with said at least one cam member and being movable thereby to bring the punch element into perforating relationship with the die element and movable also a sufficient amount to clear the surface of the web carried by the web-supporting wheel, and each said die element having a wall portion or portions cooperating with the corresponding perforator arm or a component fixedly secured thereto thereby to provide an exact guidance therefor at least in the lateral direction before the punch or punches of the associated punch element contact the web located on the die element,

means for cut-out slug removal, and

means for rotating said web-supporting wheel.

The punch elements of each perforator may be supported by a support arm which is pivotally journalled in respect of the base member and the lateral walls of which cooperate with the mentioned wall portions of the die element to receive a lateral guidance.

However, the punch elements may also be supported by perforator arms which are mounted for displacement in directions which run parallel to and radially of the axis of the web-supporting wheel, and in such case the perforator arm is preferably provided with positioning means fixedly secured thereto and arranged to cooperate with the mentioned wall portions of the die element to afford a lateral as well as a forward guidance for the punch element in respect of the die.

Individual die elements may be serviced by grinding off the top face for restoring the exact hole size, and the exact location of the top face of die elements which thus have been restored in respect of the base members may be obtained through the insertion of spacer plates of appropriate thickness.

Each base member may comprise one polished end face which abuts against a ring member fitted to one side of the film-supporting wheel, to thereby locate the different punch elements supported by the base members exactly in axial direction.

Adjusting means may be provided for adjusting the position of the cam members at least at one angular position to control thereby the depth over which the punches enter the dies at the perforating of the film.

The mechanism through which the punch elements are fastened to the support arms preferably permits a displacement of the punch elements over some millimeters in the direction of the longitudinal axis of the punches, so that thereby the depth of perforation of the punch elements may be adjusted individually.

The examination of a serviced perforator assembly may occur in the workshop, and if the examination reveals that the top faces of the die elements have the exact height and that the punches smoothly engage the corresponding punch holes in the die member, it is certain that the location of a die in respect of the web-supporting wheel will be right because the base member of a perforator assembly forms in fact a part of the web-supporting wheel. The base members need only an accurate mounting on the wheel after their removal for servicing the assembly, and, preferably, each base member is remounted at its previous position on the wheel circumference.

When the pitch of the perforations of the web amounts to small values, such as 3.81 mm in the case of8 mm or 4.75 mm in the case of 35 mm film it may be materially impossible to let each arm support only one punch, and in such case the perforator arms may support a punch element having two or more punches located in one plane for making one row of perforations.

The punches may be fixedly secured to the punch element they preferably form one'part therewith and their axis must necessarily run parallel to each other in such a way to allow the introduction of the punches in the correspondin g die openings.

However, the punches may also be arranged for displacement according to their longitudinal axis in respect of a common punch holder, and in such case the exact guidance which is imposed by the mentioned wall portions of the die element applies to the arm supporting said common punch holder.

While the invention is disclosed with respect to apparatus for perforating film, it is to be understood that the invention can be applied equally well to apparatus for perforating other strip materials which lend themselves thereto, such as paper tape, magnetic tape, etc.

The invention will now be described with reference to the accompanying drawings, wherein FIG. 1 is a side elevation in longitudinal section of one embodiment of the rotary perforating apparatus according to the present invention.

FIG. 2 is a front view of the apparatus, the right-hand half of which is shown in section.

FIG. 3 is a sectional view in detail of a perforator assembly.

FIG. 4 is a plan sectional view of a perforator assembly.

FIG. 5 is a side elevation, and

FIG. 6 is a front view of a base member, the corresponding die element being represented in separated position.

FIG. 7 is an enlarged view of a transverse section of a part of the film-supporting wheel, through a row of die openings, respectively, through a suction opening.

FIG. 8 is a side elevation.

FIG. 9 is a front view of a support arm with a punch element.

FIG. 10 is a sample of the perforated film.

FIG. 11 is a partial side elevation shown in longitudinal section of part of another embodiment of the apparatus according to the present embodiment.

FIG. 12 is a partial front view of a perforator assembly according to FIG. 11.

FIG. 13 is a partial plan view of a perforator assembly according to FIG. 11.

Referring to FIGS. 1 and 2, the perforating apparatus comprises a main shaft 10 which is rotatably journalled in a stationary bushing 13 through conical roller bearings 11 and 12 which are sealed by oil seal rings 14 and 15. The bushing 13 is pressed in an upstanding wall 16 of generally elongate triangular shape and fixedly attached thereto by set screws, one of which is shown at 23. An opposite wall 17 is fitted in spaced parallel relationship to the wall 16 by means of three spacer bushings l8 and cooperating stud screws 19 with a collar 35, and the frame so formed is supported by a stationary machine frame 20. By loosening the nuts 21 the entire mechanism may be readily withdrawn from the frame 20, after removal of the driving gear from the shaft extremity 22, for servicing or replacement.

Circular cam rings 24 and 25 are attached to the interior side of the walls 16 and 17 by means of set screws 26 and 27. The thickness of the outer wall portions of the cam rings is slightly reduced over a radial portion, so that a clearance 28 and 29 of some millimeters is created between the outer annular part of the cam rings and the adjacent walls.

An adjustment screw 30 and a similar screw 31 at the opposite side of the apparatus are in threaded engagement with the walls 16 and 17 and they permit to exert a pressure on the cam rings to thereby slightly displace the upper part of one cam ring towards the opposite cam ring. The adjustment screws have surfaces thereon engageable by a tool to permit rotation thereof, and they may be locked through an appropriate nut.

A sector 34 of each cam ring is removable, so that through the opening thus formed the perforator assemblies which will be described hereinafter, may be radially removed with respect to the shaft without need for completely disassembling the apparatus.

The film-supporting wheel 35 is fitted to the shaft 10 by heat-shrinking and is machined around the entire outside expanse with a multiplicity of axially aligned grooves 37 (see also FIG. 7) which are adapted to support the perforator assemblies in fixed circumferential relationship with respect to each other. The perforators (FIGS. 3 to 8) comprise a base member 38 which is provided with a tongue 39 which fits within the grooves 37, and thereby accurately determines the angular position of the perforator. One end face 40 of the base member is accurately planed, and serves as a reference plane to determine the axial position of the perforator by abutment against the planed ring 41 which is fitted by circumferentially spaced set screws 43 to the left-hand side of the film-supporting wheel according to FlGS. 1 and 3.

At the opposite side of the wheel, another ring 42 is provided the cross-section and the machining of which are less than that of the ring 41, and which is fitted to the wheel side by screws 44 which engage the wheel portions located between the grooves 37. Said ring 42 only serves to press the base members with their reference plane tightly against ring 41, and after the base members have been so positioned, they are retained in position by fastening screws 45, 46.

The base member 38 has two upstanding walls 47 and 48 (FIGS. and 6), each with elevated end portions 49 and 50, and a lower located central portion 51. The adjacent end portions 49 and 50 are provided with an opening into which fits the pin for the pivotally journalling of the perforator arms.

The die element 52 which fits in said base member, and which for the sake of clearness has been drawn in a position remote from the base member in FIGS. 5 and 6, has a tongue 53 which snugly fits between the walls 47 and 48 to thereby secure the lateral position of the die element. The longitudinal position of the die element is secured by the extending lip portions 54 and 55 which abut against the elevated wall portions 49 and 50. The position of the film on the web-supporting wheel is determined by the abutment of one film edge against the edge 57 of an elevated portion of each die element.

The die element used in the present apparatus was intended for perforating film having a width of 32 mm which, after the perforating, is sliced up in two conventional 16 mm film webs, each having one row of perforations at one edge (see FIG.

The die element has two rows of three punch holes 71 and 72, and a central suction cavity 91 which will be described later in the description. The die element is finally secured to the base member through screws 56 (FIG. 3).

Two support arms 58 and 59 (FIGS. 3, 4 and 8) are pivotally secured to each base member 38, through ball bearings 61 and 62 which are pressed in the bore 63 of each arm and which are supported by pins 64 and 65 which fit into the openings of the end portions 49 and 50 of the base member.

The lower portion 66 of each perforator arm which fits between the upstanding walls 47 and 48 of each base member has reduced cross-section, whereas the upper portion 67 has a greater width and has a planed surface the lateral boundaries of which are determined by the elevated walls 68 and 69 (FIGS. 8 and 9). A punch element 70 is constituted as a rectangular steel body at the upper and the lower end with symmetrical sets of three punches 74 and 75 which cooperate with the punch openings in the die element. The punch element is fixed to the perforator arm by locking screws 76 which pass through elongate openings in the punch elements and which thus enable a vertical adjustment of the punch elements. This adjustment is facilitated by the adjustment screw 77 which permits to exert a pressure on the top face of the punch element and through which the punch element may be gradually lowered, the screws 76 being somewhat loosened, until the exact perforating depth is reached whereupon the screws 76 may be locked.

The pivotation of the perforator arms is controlled by rollers 78 which are rotatably journalled on one extremity of the perforator arms and the position of which is controlled by the camming surfaces 79 and 80 of the cam rings 24 and 25 (FIG. 3).

The exact lateral guidance of a perforator arm is assured by the opposed inner faces of the lips 54 and 55 of the die element which are accurately ground and which engage the lower shoulder portions 81 of the perforator arms in closely matching sliding relationship.

The exact radial guidance of a perforator arm is assured by the ball bearings 61 and 62 the play of which in the radial direction is almost zero, as known. The play of the bearings, however, in the axial direction permits the exact lateral guidance of the arms by the engagement of the shoulder portion by the die lips as described, and it should be understood in this connection that the play between the perforator arm and the wall portions 49 and 50 should be sufiicient to permit such exact lateral guidance of the arms.

In the construction of the apparatus, the hardness of the material, or more precisely, of the faces of the perforator arm which enter in sliding contact with the die lips, shall be greater than that of the die lips so that effects of wear during the operation of the apparatus will be limited to the lip faces only, and the periodic replacement of a die element when the deformation of the punch holes exceeds the admissible tolerances, automatically will entail a renewal of the lateral guidance faces for the perforator arm.

The described guidance of the arm constitutes a marked improvement over the lateral arm guidance through the elevated wall portions 49 and 50 of the base member only, since the precision thereof gradually decreases with the life of the perforator mechanism and thereby also reduces furthermore the effective life of each new die element which is substituted in the base member.

The mentioned condition, that the mechanical wear must be substantially limited to the die lips, does not raise any difficulties, since in practice the die element of a perforator assembly is in fact its weakest part particularly compared to of the punch element, the punch needles should outlive several die elements.

Typical values of the Rockwell hardness of the different parts are 62 for the punches, 42 for the die elements and 62 for the perforator arms.

Referring to FIGS. 3 and 7 especially, shaft 10 is provided with a drilled passage 83 which communicates through a generally radial passage 84 with the annular clearance 85 between the shaft and the inner periphery of wheel 35. The wheel 35 is provided with a number of vacuum passages which are radially disposed and which, in the present case, for the purpose of making two rows of perforations, are located in two planes, one passage of each plane being indicated by the numeral 86, respectively 87, in FIG. 3.

The die members 52 are provided with passages 88, which communicate with passages 89 in the base members 38. It may be seen in FIG. 7 that each central passage 89 communicates with one passage 86 in the wheel, whereas outer passages 89 of two adjacent base members communicate with the cylindrically widened inlet opening 102 of one passage 86. Thus, the course of the slugs is from the perforators through the punch opening of the die elements 52, through the passages 88, 89 and 86 in sequence, further through openings 85, 84 into the drilled passage 83 and out to the right through a stationary hood 90 (FIG. 1) maintained under vacuum by equipment not shown.

A second vacuum system provides therefor that the film is firmly held against the die elements at the moment of withdrawal of the punches from the film.

This is accomplished by an elongate cavity 91, shown in cross-hatching in the drawings, which is provided in each die element 52, and which communicates with the annular opening 96 in the ring member 97 through passages 92, 93 and 94, and through passages 95 which are drilled axially of the wheel and which communicate with the passages 94. Said ring member 97 is mounted for movement merely in the axial direction and is urged by a plurality of circumferentially spaced pressure springs 98 against the right-hand face of the wheel according to FIGS. 1 and 3. The ring face which contacts the wheel shows sufficient low friction properties and it ensures the air-tight sealing of the opening 96 in respect ofthe wheel. The opening 96 has a cross-section as shown in FIG. 3, and seen in plan view, it extends over an arc of about 180 angular degrees. The opening 96 is maintained under vacuum through a conduit 99 which is connected to a second equipment, not shown, the duty of which may be lower, but the underpressure developed thereby must be higher than that of the vacuum equipment used for the slug removal.

Referring to FIGS. 1, 2 and 4, the operation of the apparatus is now described for the case of clockwise rotation of the film-supporting wheel, although it will be understood that operation in the reverse direction is equally feasible if the direction of feed of the film is reversed.

The diameter of the circular periphery on which the film is supported amounts to 218.28 mm, 30 perforator assemblies are provided on the wheel, and the perforator arm of each assembly supports a punch element with three parallel punches as described hereinbefore.

The film-supporting wheel 35 is driven at a constant speed through a driving wheel which is mounted at the shaft extremity 22, and which may be a sprocket wheel driven through a chain, a gear in engagement with a timing belt, or the like,

The film is fed to the wheel over rollers which are braked through a slip clutch so that a constant film tension is ensured. In the same way, the film is pulled from the wheel by rollers driven over a slip-clutch so that a constant web tension is obtained.

The unperforated film 60 enters the apparatus in the vicinity of the 7 O'clock position (FIG. 2) by conveyance around a guide roller 101 shown in broken lines and journalled on the framework of the apparatus. The perforators are in fully retracted position at this point and thus the film is led onto the surface of the die elements on the wheel without interference from the perforators.

The film contacts the die elements 52 at about the 8 oclock position and is applied with one edge against the upstanding rim 57 of each die element by appropriate lateral conveyance by the roller 101. The film follows the wheel periphery until about the 4 oclock position where the film looses contact with the wheel and is led to a winding device, not shown. From the above it will be understood that perforation is performed during rotation of the wheel over about 240 angular degrees of rotation of the wheel, which affords ample time for the operation, even at film speeds up to I50 m/min.

The punches of the perforators are in fully depressed position at the 12 o'clock position, the inward movement of the perforator arms taking place from 8 to 12 oclock position. The cutout film slugs are sucked through the radial passages 88, 89 and 86 into the annular opening and drawn off through the central hood 90 to a suitable collector. In connection with the removal of the film slugs it may be interesting to refer to the enlarged sectional view shown in FIG. 7, wherein it can be seen that the enlarged bore 102 of a passage 86 does not only communicate with the passages 89 of two adjacent base members but, on the contrary, communicates also with the ambient atmosphere through the small clearance 103 which exists between the lateral walls of adjacent base members 38. In addition, the connections between the central passages 88, 89 and 86 also communicate with the ambient atmosphere through the clearances 107 and 108 between the die elements, the base members and the film-supporting wheel, respectively.

As a consequence of the air leakage through said clearances, a sufiicient air velocity is always maintained passing from the die openings towards the annular opening 85 of the wheel, in spite of the fact that in operation of the apparatus the upper parts of the passages 88 are almost closed by the film slugs entered therein, and the removal of the film slugs can occur at sufficiently high speed without need for an increased vacuum.

During the retraction of the arms from the 12 to the 4 oclock position of the wheel, the film is firmly held against the curved upper surface of the die elements through the underpressure which prevails in the cavities 91. This measure leads to perforations of higher precision, since during their retraction the punches cannot lift the film from the die elements, and damage thereby the edges of the perforations.

When the film has been perforated as described hereinbefore, it looks like the sample as shown in FIG. 10 and, preferably before it is wound on a reel, it is slit longitudinally along a longitudinal line 104 indicated in broken lines, so that two single edge-perforated 16 mm films are obtained which may be wound on two separate reels.

When in the operation of the apparatus one or more punches of a perforator assembly have been accidentally demaged, the replacement of the perforator assembly occurs as follows. The apparatus being arrested and the film loop removed, the operator turns the film-supporting wheel until the defective perforator is located at about the 3 oclock position (FIG. 2). The sector 34 of both cam rings is removed, the screws 45 and 46 are removed, the screws 44 adjacent to the perforator are loosened, and the perforator assembly is taken out of the apparatus. In case the punches have been damaged, the punch element may be removed, turned over 180 degrees and mounted again. The accurately ground faces of the punch element engage the corresponding faces of the support arm and they secure the exact positioning of the punch element, except for its height. In case the punch holes of the die element 52 have been damaged, the die element may be replaced by a new one, or the holes of the die element may be reshaped by grinding off the upper side of the die element over a few tenths of a millimeter on an appropriate caliber so that the curvature of said side has the right value, and by remounting said die element on one or more spacer plates as indicated by the numeral in FIG. 7 in order to re-establish the exact location of the upper side of the die element in respect of the wheel.

The adjustment of the height of the punch element occurs in slightly loosening the fixing screws 76, and in slowly screwing the screw 77 which lowers the punch element until the exact height is reached, whereafter the screws 76 are tightened and the adjustment screw 77 is locked in respect of the body of the perforator arm by means of the corresponding nut.

The exact height of the punch element may be checked in two ways. In a first way the perforator assembly may be mounted in a caliber wherein the perforator arms are made to take a position which corresponds to their 12 oclock position in the apparatus. The operator lowers the punch element until the punches enter over the required distance, generally some tenths of a millimeter, the punch holes.

in a second way, the perforator assembly may be mounted in the wheel, and the wheel rotated so that the perforator becomes located at a determined angular position at which the punches are remote from the die element over a determined small distance. A thickness caliber is put on the die element and the punch element is lowered until abutment against the caliber occurs, whereupon the punch element may be locked and the caliber may be removed.

When all the die elements must be adjusted, the perforator arms may be removed, the die elements removed and mounted again on spacer plates 105 of a certain thickness, and the top face of the die elements ground off by mounting the wheel in a grinding machine and by rotating the wheel in front of a rotating grinding stone.

The individual adjustment of the height of each punch element in the case of a general revision of the apparatus may be facilitated by loosening the adjustment screws 30 and 31 which control the position of the cam rings at the 12 clock position so that the cam rings are removed from each other at that position and the punches no longer enter the die element. A flexible steel band of a thickness of some tenths of a millimeter is located around the wheel, and the punch elements of each perforator are adjusted so that at the 12 o'clock position each punch just touches the steel band located on the die elements. When all the punch elements have received the same relative adjustment in the described way, the steel band is removed and the screws 30 and 31 are tightened so that the angular position of the perforator arms is increased with a determined amount and the punches enter the holes of the dies at the 12 oclock position over the required distance.

Alternatively, the adjustment of the position of the cam rings at the perforating zone permits also to compensate the effects of wear of the cam tracks 79 and 80, of the rollers 78, etc.

It will be apparent that the perforation of the film by means of punch elements carrying each three punches which run strictly parallel to each other and which penetrate through the film while the latter is curved according to the wheel circumference, cannot yield perfect perforations in the film since the walls of the central perforation of each set of three perforations will be normal to the film whereas the walls of the two outer perforations of each set will be slanting towards the film surface when the film is rendered flat after the perforating. It can be shown, however, that the error in pitch which is introduced in the mentioned way is small in comparison with the tolerances of the size of the punches-and the die holes which are encountered in practice.

When greater accuracy is yet required the number of punches per perforator arm may be reduced to two, and it is quite evident that in case only one punch per arm is provided, theoretically perfect perforations may be obtained. The latter arrangement, however, is reserved for apparatus for perforating films with a relatively great pitch between the perforations, since e.g. even a pitch of 7.62 mm as in the case of 16 mm film described hereinbefore, does not allow the provision of only one punch per perforator arm.

An embodiment of the apparatus according to the present invention wherein the punches are arranged for performing displacements in directions which are parallel to and radiaily of the axis of the web-supporting wheel, rather than performing a pivoting movement as described hereinbefore, is described hereinafter with reference to FIGS. 11 to 13.

The general concept of the apparatus corresponding almost to that of the apparatus described in connection with FIGS. 1 to 9, only the modified elements are illustrated in the FIGS. 11 to 13.

Taking reference to FIGS. 11 to 13, the wheel is provided with a plurality of circumferentially spaced sets of two parallel guide pins 111 and 112 which slideably support a base 113 the position of which is controlled by rollers 114 which cooperate with cam track 115.

Five sets of two parallel guide pins 116 and 117, the axis of which intersect the wheel axes under a right angle, are fitted to each base, and each set of pins slideably supports a perforator arm 118. Compression springs 119 and 120 are provided between each perforator arm and the base, and they ensure the position of the perforator arm 118 remote from the base 113 when the arm is in the inoperative position. The movement of each perforator arm in a direction towards the wheel axis is controlled by rollers 121 and 122 which cooperate with a cam track 123. Said can track only extends between the 9 and 3 oclock position of the wheel, the perforator arms being kept in the remote position from the 3 to the 9 oclock position by the mentioned springs 119 and 120. Each perforator arm supports a punch element 124 which is provided with two rows of three parallel punches which may cooperate with a die element 125 to form at each operation six perforations in the film of the type as shown in FIG. 10. The die element is supported by a base member 126 which fits in a corresponding groove of the wheel, in a way similar to the apparatus described in FIGS. 1 to 9.

The lower front portion of the perforator arms is recessed and is provided with two fixed studs 127, made of hardened steel, Rockwell hardness 62, which have a tapered head and which engage corresponding bores 128 in the die element, hardness 42, to thereby exactly determine the relative position punch element to die element as the punch element is lowered.

In the operation of the apparatus, the perforator arms are retracted in the direction parallel to the wheel axis from the 4 to the 8 o'clock position so that the film may be led to and removed from the apparatus without interference with the punch elements. From the 8 to the 10 oclock position the bases 113 are approached towards the die elements and remain in that position until reaching about the 2 o'clock position. Up from the 10 oclock position, the perforator arms are gradually lowered and as they pass the 12 oclock position the different perforator arms of each base are actuated in succession to perforate the film.

The cooperation of the studs 127 with the corresponding bores 128 in the die elements ensures the right location of the punches in the axial as well as in the tangential direction in respect of the wheel, so that the mechanical play in the different sliding guidances of the perforator arm do not disadvantageously influence the perforation quality. During the further rotation of the wheel, the perforator arms are lifted and retracted so that the perforated film may be withdrawn from the wheel.

It will be understood that in the present apparatus cam 123 may have a track such that the perforator arms of one base may be moved practically together into perforating relationship with the corresponding die so that a plurality of punches function as sprocket teeth to secure the position of the web in respect of the wheel.

The invention is not limited to the embodiments described.

The positive control of the arms supporting the punch elements by means of cams which both push and pull the guide rollers of the arms, may be replaced by a control according to which the arms are positively urged into the perforating position, the withdrawal of the arms occurring however, through spring means.

The channels which are provided for the removal of the slugs may have other forms than those shown. Thus the radial opening 84 which communicates with the channel 83 may be replaced by a plurality of circumferentially spaced springs. The passages 89 and 86 may have a uniform cross-section rather than the cylindrical form shown which tapers into a widened inlet opening, and it has been found indeed, that the presence of widened portions in such channels may occasionally be inconvenient to the smooth slug removal.

The element on the perforator arm which cooperates with the wall portions of the die element may occasionally be arranged for replacement by a new one. In such a way effects of wear which in the long run may also appear on this element, may be overcome.

It should be understood that such replacement is not possible in the apparatus as described in connection with FIGS. 1 to 9 unless the complete arm is replaced, but, on the contrary, may be done in the apparatus shown in FIGS. 11 to 13 wherein it relates to the studs 127.

The cooperation between the perforator arm and the die element for securing the exact guidance, may be obtained through two elements which each provide a guidance in one direction and which, as the case may be, can operate in succession.

Thus, in the apparatus according to FIGS. 11 to 13, the vertical recessed portion of the perforator arm 118 which is at the left side of the studs 127 may be provided with a rectangularly projecting lip to engage a corresponding recess in the adjacent of the die element 125, which recess may be similar to the opening determined by the lips 54 of the die elements 52 in the apparatus according to FIGS. 1 to 9.

Further, the studs 127 may be replaced by a flat lip member extending in a plane normal to the wheel axis and having bevelled edges at the free end, and the bores 128 may be widened to form elongate slots adapted for engagement by the mentioned lip members upon lowering of the arm.

As the perforator ann is moved towards the die element in the direction parallel to the wheel axis, the first described lip engages the recess in the die element and thereby accurately determines the relative position between the arm and the die element in the direction normal to the plane passing through the axis ofthe pins 116 and 117.

As the perforator arm is lowered, the additional positioning in the direction parallel to the wheel axis occurs through the engagement of the mentioned second lip members with the elongate slots in the die elements.

We claim:

1. A rotary perforating apparatus comprising in combination:

a frame;

at least one cam member carrying a camming surface fixedly mounted on said frame;

a web-supporting wheel rotatably journalled in said frame;

a plurality of web perforator assemblies secured to the outside periphery of said web-supporting wheel in fixed circumferentially spaced relation to each other, each web perforator assembly comprising a base member, at least one operator arm movable relative to said base member a replaceable punch element supported on said arm, and a replaceable cooperating die element secured to the base member, each said operator arm being engaged by the camming surface of each such cam member and being movable thereby to bring the punch element into and away from perforating relationship with the die element, and each die element having at least one wall portion cooperating with the corresponding operator arm or a component fixedly connected thereto to provide exact guidance therefor at least in a direction lateral to the plane of movement of the arm before the associated punch element contacts the web supported on the die element;

means for removing the slugs cut out from said web; and

means for rotating said web-supporting wheel.

2. A rotary perforating apparatus according to claim 1 wherein each operator arm is pivotally journalled between upstanding wall portions of the base member with a lateral clearance therebetween which is sufiiciently great to accommodate the exact lateral positioning of the ann by such portions of the die element.

3. A rotary perforating apparatus according to claim 2 wherein each die element has opposed lip portions which extend from the body of the die element towards the pivotal axis of the operator arm and the inner faces of said lip portions cooperate with the corresponding operator arm for effecting said lateral guidance.

4. A rotary perforating apparatus according to claim 3, wherein said inner faces slidingly engage lateral wall portions of the perforator arm.

5. A rotary perforating apparatus according to claim 1, wherein spacer plates are provided between the underside of the die elements and the base members.

6. A rotary perforating apparatus according to claim 1, wherein the punch elements are attached on the operator arms for adjustment in the direction of the punch axis.

7. A rotary perforating apparatus according to claim 6 wherein the punch elements carry a plurality of punches in symmetrical arrangement at each of the opposite ends thereof.

8. A rotary perforating apparatus according to claim 2 wherein each base member carries two pivotable operator arms and associated punch elements which cooperate with and receive lateral guidance from a common die element.

9. A rotary perforating apparatus according to claim I, wherein the cam member includes a removable sector to enable removal of a perforator assembly in a direction generally radially of the web supporting wheel axis.

10. A rotary perforating apparatus according to claim 1 including an operator arm support mounted for movement in a direction parallel to the wheel axis, and means mounting said operator arm on said support for movement in a direction radially of the wheel, and wherein two cam members are provided, one controlling the axial position of said support and the other controlling the radial position of the operator arm.

11. A rotary perforating apparatus according to claim 10 wherein at least one aligning pin is fitted to the operator arm for engaging a corresponding opening in the die element as the punch element is moved to operative position for exactly positioning the punch element relative to the die element.

12. A rotary perforating apparatus according to claim 11 wherein said at least one aligning pin has a tapering free end to facilitate the correct relative positioning of the punch element and die element as the punch element is moved to operating position.

13. A rotary perforating apparatus according to claim 10, wherein each punch element carries at least two punches which are spaced from each other in the direction of the axis of the film supporting wheel to thereby produce two rows of perforations on the web.

14. A rotary perforating apparatus according to claim 13, wherein adjustment means is provided for adjusting the position of the cam members to thereby adjust the distance over which the operator arms carrying the punch elements are moved towards the die elements.

15. A rotary perforating apparatus according to claim 1 wherein cavities are provided in the die elements in the region thereof which is covered by the web and including means for maintaining in these cavities a vacuum for securing the web against displacement relative to the web-supporting wheel at least during the withdrawal of the punches from the perforations. 

1. A rotary perforating apparatus comprising in combination: a frame; at least one cam member carrying a camming surface fixedly mounted on said frame; a web-supporting wheel rotatably journalled in said frame; a plurality of web perforator assemblies secured to the outside periphery of said web-supporting wheel in fixed circumferentially spaced relation to each other, each web perforator assembly comprising a base member, at least one operator arm movable relative to said base member a replaceable punch element supported on said arm, and a replaceable cooperating die element secured to the base member, each said operator arm being engaged by the camming surface of each such cam member and being movable thereby to bring the punch element into and away from perforating relationship with the die element, and each die element having at least one wall portion cooperating with the corresponding operator arm or a component fixedly connected thereto to provide exact guidance therefor at least in a direction lateral to the plane of movement of the arm before the associated punch element contacts the web supported on the die element; means for removing the slugs cut out from said web; and means for rotating said web-supporting wheel.
 2. A rotary perforating apparatus according to claim 1 wherein each operator arm is pivotally journalled between upstanding wall portions of the base member with a lateral clearance therebetween which is sufficiently great to accommodate the exact lateral positioning of the arm by such portions of the die element.
 3. A rotary perforating apparatus according to claim 2 wherein each die element has opposed lip portions which extend from the body of the die element towards the pivotal axis of the operator arm and the inner faces of said lip portions cooperate with the corresponding operator arm for effecting said lateral guidance.
 4. A rotary perforating apparatus according to claim 3, wherein said inner faces slidingly engage lateral wall portions of the perforator arm.
 5. A rotary perforating apparatus according to claim 1, wherein spacer plates are provided between the underside of the die elements and the base members.
 6. A rotary perforating apparatus according to claim 1, wherein the punch elements are attached on the operator arms for adjustment in the direction of the punch axis.
 7. A rotary perforating apparatus according to claim 6 wherein the punch elements carry a plurality of punches in symmetrical arrangement at each of the opposite ends thereof.
 8. A rotary perforating apparatus according to claim 2 wherein each base member carries two pivotable operator arms and associated punch elements which cooperate with and receive lateral guidance from a common die element.
 9. A rotary perforating apparatus according to claim 1, wherein the cam member includes a removable sector to enable removal of a perforator assembly in a direction generally radially of the web supporting wheel axis.
 10. A rotary perforating apparatus according to claim 1 including an operator arm support mounted for movement in a direction parallel to the wheel axis, and means mounting said operator arm on said support for movement in a direction radially of the wheel, and wherein two cam members are provided, one controlling the axial position of said support and the other controlling the radial position of the operator arm.
 11. A rotary perforating apparatus according to claim 10 wherein at least one aligning pin is fitted to the operator arm for engaging a corresponding opening in the die element as the punch element is moved to operative position for exactly positioning the punch element relative to the die element.
 12. A rotary perforating apparatus according to claim 11 wherein said at least oNe aligning pin has a tapering free end to facilitate the correct relative positioning of the punch element and die element as the punch element is moved to operating position.
 13. A rotary perforating apparatus according to claim 10, wherein each punch element carries at least two punches which are spaced from each other in the direction of the axis of the film supporting wheel to thereby produce two rows of perforations on the web.
 14. A rotary perforating apparatus according to claim 13, wherein adjustment means is provided for adjusting the position of the cam members to thereby adjust the distance over which the operator arms carrying the punch elements are moved towards the die elements.
 15. A rotary perforating apparatus according to claim 1 wherein cavities are provided in the die elements in the region thereof which is covered by the web and including means for maintaining in these cavities a vacuum for securing the web against displacement relative to the web-supporting wheel at least during the withdrawal of the punches from the perforations. 